QwtPlotIntervalCurve - QwtPlotIntervalCurve represents a series of samples, where each value is associated with an interval ( $[y1, y2] = f(x)$ ).

NAME

QwtPlotIntervalCurve − QwtPlotIntervalCurve represents a series of samples, where each value is associated with an interval ( $[y1,y2] = f(x)$ ).

SYNOPSIS

#include <qwt_plot_intervalcurve.h>

Inherits QwtPlotSeriesItem, and QwtSeriesStore< QwtIntervalSample >.

Public Types

enum CurveStyle { NoCurve, Tube, UserCurve = 100 }
Curve styles. The default setting is QwtPlotIntervalCurve::Tube.
enum PaintAttribute { ClipPolygons = 0x01, ClipSymbol = 0x02, TubeAsLines = 0x10 }
typedef QFlags< PaintAttribute > PaintAttributes

Public Types inherited from QwtPlotItem

enum RttiValues { Rtti_PlotItem = 0, Rtti_PlotGrid, Rtti_PlotScale, Rtti_PlotLegend, Rtti_PlotMarker, Rtti_PlotCurve, Rtti_PlotSpectroCurve, Rtti_PlotIntervalCurve, Rtti_PlotHistogram, Rtti_PlotSpectrogram, Rtti_PlotGraphic, Rtti_PlotTradingCurve, Rtti_PlotBarChart, Rtti_PlotMultiBarChart, Rtti_PlotShape, Rtti_PlotTextLabel, Rtti_PlotZone, Rtti_PlotVectorField, Rtti_PlotUserItem = 1000 }
Runtime type information.
enum ItemAttribute { Legend = 0x01, AutoScale = 0x02, Margins = 0x04 }
Plot Item Attributes.
enum ItemInterest { ScaleInterest = 0x01, LegendInterest = 0x02 }
Plot Item Interests.
enum RenderHint { RenderAntialiased = 0x1 }
Render hints.
typedef QFlags< ItemAttribute > ItemAttributes
typedef QFlags< ItemInterest > ItemInterests
typedef QFlags< RenderHint > RenderHints

Public Member Functions

QwtPlotIntervalCurve (const QString &title=QString())
QwtPlotIntervalCurve (const QwtText &title)
virtual ˜QwtPlotIntervalCurve ()
Destructor.
virtual int rtti () const override
void setPaintAttribute (PaintAttribute, bool on=true)
bool testPaintAttribute (PaintAttribute) const
void setSamples (const QVector< QwtIntervalSample > &)
void setSamples (QwtSeriesData< QwtIntervalSample > *)
void setPen (const QColor &, qreal width=0.0, Qt::PenStyle=Qt::SolidLine)
void setPen (const QPen &)
Assign a pen.
const QPen & pen () const
void setBrush (const QBrush &)
const QBrush & brush () const
void setStyle (CurveStyle style)
CurveStyle style () const
void setSymbol (const QwtIntervalSymbol *)
const QwtIntervalSymbol * symbol () const
virtual void drawSeries (QPainter *, const QwtScaleMap &xMap, const QwtScaleMap &yMap, const QRectF &canvasRect, int from, int to) const override
virtual QRectF boundingRect () const override
virtual QwtGraphic legendIcon (int index, const QSizeF &) const override

Public Member Functions inherited from QwtPlotSeriesItem

QwtPlotSeriesItem (const QString &title=QString())
QwtPlotSeriesItem (const QwtText &title)
virtual ˜QwtPlotSeriesItem ()
Destructor.
void setOrientation (Qt::Orientation)
Qt::Orientation orientation () const
virtual void draw (QPainter *, const QwtScaleMap &xMap, const QwtScaleMap &yMap, const QRectF &canvasRect) const override
Draw the complete series.
virtual void updateScaleDiv (const QwtScaleDiv &, const QwtScaleDiv &) override
Update the item to changes of the axes scale division.

Public Member Functions inherited from QwtPlotItem

QwtPlotItem ()
QwtPlotItem (const QString &title)
QwtPlotItem (const QwtText &title)
virtual ˜QwtPlotItem ()
Destroy the QwtPlotItem.
void attach (QwtPlot *plot)
Attach the item to a plot.
void detach ()
This method detaches a QwtPlotItem from any QwtPlot it has been associated with.
QwtPlot * plot () const
Return attached plot.
void setTitle (const QString &title)
void setTitle (const QwtText &title)
const QwtText & title () const
void setItemAttribute (ItemAttribute, bool on=true)
bool testItemAttribute (ItemAttribute) const
void setItemInterest (ItemInterest, bool on=true)
bool testItemInterest (ItemInterest) const
void setRenderHint (RenderHint, bool on=true)
bool testRenderHint (RenderHint) const
void setRenderThreadCount (uint numThreads)
uint renderThreadCount () const
void setLegendIconSize (const QSize &)
QSize legendIconSize () const
double z () const
void setZ (double z)
Set the z value.
void show ()
Show the item.
void hide ()
Hide the item.
virtual void setVisible (bool)
bool isVisible () const
void setAxes (QwtAxisId xAxis, QwtAxisId yAxis)
void setXAxis (QwtAxisId)
QwtAxisId xAxis () const
Return xAxis.
void setYAxis (QwtAxisId)
QwtAxisId yAxis () const
Return yAxis.
virtual void itemChanged ()
virtual void legendChanged ()
virtual void getCanvasMarginHint (const QwtScaleMap &xMap, const QwtScaleMap &yMap, const QRectF &canvasRect, double &left, double &top, double &right, double &bottom) const
Calculate a hint for the canvas margin.
virtual void updateLegend (const QwtPlotItem *, const QList< QwtLegendData > &)
Update the item to changes of the legend info.
QRectF scaleRect (const QwtScaleMap &, const QwtScaleMap &) const
Calculate the bounding scale rectangle of 2 maps.
QRectF paintRect (const QwtScaleMap &, const QwtScaleMap &) const
Calculate the bounding paint rectangle of 2 maps.
virtual QList< QwtLegendData > legendData () const
Return all information, that is needed to represent the item on the legend.

Public Member Functions inherited from QwtAbstractSeriesStore

virtual ˜QwtAbstractSeriesStore ()
Destructor.

Public Member Functions inherited from QwtSeriesStore< QwtIntervalSample >

QwtSeriesStore ()
Constructor The store contains no series.
˜QwtSeriesStore ()
Destructor.
void setData (QwtSeriesData< QwtIntervalSample > *series)
QwtSeriesData< QwtIntervalSample > * data ()
const QwtSeriesData< QwtIntervalSample > * data () const
QwtIntervalSample sample (int index) const
virtual size_t dataSize () const override
virtual QRectF dataRect () const override
virtual void setRectOfInterest (const QRectF &rect) override
QwtSeriesData< QwtIntervalSample > * swapData (QwtSeriesData< QwtIntervalSample > *series)

Protected Member Functions

void init ()
Initialize internal members.
virtual void drawTube (QPainter *, const QwtScaleMap &xMap, const QwtScaleMap &yMap, const QRectF &canvasRect, int from, int to) const
virtual void drawSymbols (QPainter *, const QwtIntervalSymbol &, const QwtScaleMap &xMap, const QwtScaleMap &yMap, const QRectF &canvasRect, int from, int to) const

Protected Member Functions inherited from QwtPlotSeriesItem

virtual void dataChanged () override
dataChanged() indicates, that the series has been changed.

Protected Member Functions inherited from QwtPlotItem

QwtGraphic defaultIcon (const QBrush &, const QSizeF &) const
Return a default icon from a brush.

Detailed Description

QwtPlotIntervalCurve represents a series of samples, where each value is associated with an interval ( $[y1,y2] = f(x)$ ).

The representation depends on the style() and an optional symbol() that is displayed for each interval. QwtPlotIntervalCurve might be used to display error bars or the area between 2 curves.

Definition at line 27 of file qwt_plot_intervalcurve.h.

Member Typedef Documentation

typedef QFlags<PaintAttribute > QwtPlotIntervalCurve::PaintAttributes

An ORed combination of PaintAttribute values.

Definition at line 98 of file qwt_plot_intervalcurve.h.

Member Enumeration Documentation

enum QwtPlotIntervalCurve::CurveStyle

Curve styles. The default setting is QwtPlotIntervalCurve::Tube.

See also

setStyle(), style()

Enumerator
NoCurve

Don’t draw a curve. Note: This doesn’t affect the symbols.

Tube

Build 2 curves from the upper and lower limits of the intervals and draw them with the pen(). The area between the curves is filled with the brush().

UserCurve

Styles >= QwtPlotIntervalCurve::UserCurve are reserved for derived classes that overload drawSeries() with additional application specific curve types.

Definition at line 38 of file qwt_plot_intervalcurve.h.

enum QwtPlotIntervalCurve::PaintAttribute

Attributes to modify the drawing algorithm.

See also

setPaintAttribute(), testPaintAttribute()

Enumerator
ClipPolygons

Clip polygons before painting them. In situations, where points are far outside the visible area (f.e when zooming deep) this might be a substantial improvement for the painting performance.

ClipSymbol

Check if a symbol is on the plot canvas before painting it.

TubeAsLines

Fill the tube with horizontal or vertical lines and unite overlapping border lines. This attribute is useful for large data sets, where consecutive samples are often mapped to the same coordinate.

Beside other minor visual differences the filling is always monochrome - using brush().color().

This algorithm is very fast and effective and can be used inside a replot cycle. In the worst case the number of lines to be rendered will be 5 times the ( width/height - depending on the orientation() ) of the plot canvas.

Note

Has only an effect, when drawing to a paint device in integer coordinates ( f.e. all widgets on screen ).

See also

QwtPlotCurve::FilterPointsAggressive

Definition at line 64 of file qwt_plot_intervalcurve.h.

Constructor & Destructor Documentation

QwtPlotIntervalCurve::QwtPlotIntervalCurve (const QString & title =QString()) [explicit]

Constructor

Parameters

title Title of the curve

Definition at line 524 of file qwt_plot_intervalcurve.cpp.

QwtPlotIntervalCurve::QwtPlotIntervalCurve (const QwtText & title)[explicit]

Constructor

Parameters

title Title of the curve

Definition at line 514 of file qwt_plot_intervalcurve.cpp.

QwtPlotIntervalCurve::˜QwtPlotIntervalCurve () [virtual]

Destructor.

Definition at line 531 of file qwt_plot_intervalcurve.cpp.

Member Function Documentation

QRectF QwtPlotIntervalCurve::boundingRect () const [override], [virtual]

Returns

Bounding rectangle of all samples. For an empty series the rectangle is invalid.

Reimplemented from QwtPlotSeriesItem.

Definition at line 734 of file qwt_plot_intervalcurve.cpp.

const QBrush & QwtPlotIntervalCurve::brush () const

Returns

Brush used to fill the area in Tube style()

See also

setBrush(), setStyle(), CurveStyle

Definition at line 725 of file qwt_plot_intervalcurve.cpp.

void QwtPlotIntervalCurve::drawSeries (QPainter * painter, constQwtScaleMap & xMap, const QwtScaleMap & yMap, const QRectF &canvasRect, int from, int to) const [override], [virtual]

Draw a subset of the samples

Parameters

painter Painter
xMap Maps x-values into pixel coordinates.
yMap Maps y-values into pixel coordinates.
canvasRect Contents rectangle of the canvas
from Index of the first sample to be painted
to Index of the last sample to be painted. If to < 0 the series will be painted to its last sample.

See also

drawTube(), drawSymbols()

Implements QwtPlotSeriesItem.

Definition at line 756 of file qwt_plot_intervalcurve.cpp.

void QwtPlotIntervalCurve::drawSymbols (QPainter * painter, constQwtIntervalSymbol & symbol, const QwtScaleMap & xMap, const QwtScaleMap& yMap, const QRectF & canvasRect, int from, int to) const [protected],[virtual]

Draw symbols for a subset of the samples

Parameters

painter Painter
symbol Interval symbol
xMap x map
yMap y map
canvasRect Contents rectangle of the canvas
from Index of the first sample to be painted
to Index of the last sample to be painted

See also

setSymbol(), drawSeries(), drawTube()

Definition at line 829 of file qwt_plot_intervalcurve.cpp.

void QwtPlotIntervalCurve::drawTube (QPainter * painter, const QwtScaleMap& xMap, const QwtScaleMap & yMap, const QRectF & canvasRect, int from,int to) const [protected], [virtual]

Draw a tube

Builds 2 curves from the upper and lower limits of the intervals and draws them with the pen(). The area between the curves is filled with the brush().

Parameters

See also

drawSeries(), drawSymbols()

Definition at line 797 of file qwt_plot_intervalcurve.cpp.

void QwtPlotIntervalCurve::init () [protected]

Initialize internal members.

Definition at line 537 of file qwt_plot_intervalcurve.cpp.

QwtGraphic QwtPlotIntervalCurve::legendIcon (int index, const QSizeF &size) const [override], [virtual]

Returns

Icon for the legend

In case of Tube style() the icon is a plain rectangle filled with the brush(). If a symbol is assigned it is scaled to size.

Parameters

index Index of the legend entry ( ignored as there is only one )
size Icon size

See also

QwtPlotItem::setLegendIconSize(), QwtPlotItem::legendData()

Reimplemented from QwtPlotItem.

Definition at line 896 of file qwt_plot_intervalcurve.cpp.

const QPen & QwtPlotIntervalCurve::pen () const

Returns

Pen used to draw the lines

See also

setPen(), brush()

Definition at line 697 of file qwt_plot_intervalcurve.cpp.

int QwtPlotIntervalCurve::rtti () const [override], [virtual]

Returns

QwtPlotItem::Rtti_PlotIntervalCurve

Reimplemented from QwtPlotItem.

Definition at line 549 of file qwt_plot_intervalcurve.cpp.

void QwtPlotIntervalCurve::setBrush (const QBrush & brush)

Assign a brush.

The brush is used to fill the area in Tube style().

Parameters

brush Brush

See also

brush(), pen(), setStyle(), CurveStyle

Definition at line 710 of file qwt_plot_intervalcurve.cpp.

void QwtPlotIntervalCurve::setPaintAttribute (PaintAttribute attribute,bool on = true)

Specify an attribute how to draw the curve

Parameters

attribute Paint attribute
on On/Off

See also

testPaintAttribute()

Definition at line 561 of file qwt_plot_intervalcurve.cpp.

void QwtPlotIntervalCurve::setPen (const QColor & color, qreal width = 0.0,Qt::PenStyle style = Qt::SolidLine)

Build and assign a pen

In Qt5 the default pen width is 1.0 ( 0.0 in Qt4 ) what makes it non cosmetic ( see QPen::isCosmetic() ). This method has been introduced to hide this incompatibility.

Parameters

color Pen color
width Pen width
style Pen style

See also

pen(), brush()

Definition at line 672 of file qwt_plot_intervalcurve.cpp.

void QwtPlotIntervalCurve::setPen (const QPen & pen)

Assign a pen.

Parameters

pen New pen

See also

pen(), brush()

Definition at line 682 of file qwt_plot_intervalcurve.cpp.

void QwtPlotIntervalCurve::setSamples (const QVector< QwtIntervalSample > &samples)

Initialize data with an array of samples.

Parameters

samples Vector of samples

Definition at line 584 of file qwt_plot_intervalcurve.cpp.

void QwtPlotIntervalCurve::setSamples (QwtSeriesData< QwtIntervalSample > *data)

Assign a series of samples

setSamples() is just a wrapper for setData() without any additional value - beside that it is easier to find for the developer.

Parameters

data Data

Warning

The item takes ownership of the data object, deleting it when its not used anymore.

Definition at line 600 of file qwt_plot_intervalcurve.cpp.

void QwtPlotIntervalCurve::setStyle (CurveStyle style)

Set the curve’s drawing style

Parameters

style Curve style

See also

CurveStyle, style()

Definition at line 612 of file qwt_plot_intervalcurve.cpp.

void QwtPlotIntervalCurve::setSymbol (const QwtIntervalSymbol * symbol)

Assign a symbol.

Parameters

symbol Symbol

See also

symbol()

Definition at line 638 of file qwt_plot_intervalcurve.cpp.

QwtPlotIntervalCurve::CurveStyle QwtPlotIntervalCurve::style () const

Returns

Style of the curve

See also

setStyle()

Definition at line 627 of file qwt_plot_intervalcurve.cpp.

const QwtIntervalSymbol * QwtPlotIntervalCurve::symbol () const

Returns

Current symbol or NULL, when no symbol has been assigned

See also

setSymbol()

Definition at line 654 of file qwt_plot_intervalcurve.cpp.

bool QwtPlotIntervalCurve::testPaintAttribute (PaintAttribute attribute)const

Returns

True, when attribute is enabled

See also

PaintAttribute, setPaintAttribute()

Definition at line 574 of file qwt_plot_intervalcurve.cpp.

Author

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Updated 2026-06-01 - jenkler.se | uex.se